Microsoft Graph: How to get the alias from an email message?

Question

When I use Microsoft Graph to retrieve a message's toRecipients or internetMessageHeaders, I am unable to find the actual email alias that the mail was sent to. How do I get the alias? It is always returning the "parent" account, never the alias account.

For example, this shows alias1@company.com as an alias to account email1@company.com.

Request:

https://graph.microsoft.com/v1.0/users/email1@company.com?$select=proxyAddresses

Response:

{
    "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users(proxyAddresses)/$entity",
    "proxyAddresses": [
        "smtp:alias1@company.com",
        "X500:/o=Org1/ou=External (xxxxx)/cn=Recipients/cn=00000000000000000000",
        "x500:/o=ExchangeLabs/ou=Exchange Administrative Group (xxxxx)/cn=Recipients/cn=1111111111111111",
        "smtp:email1@company.mail.onmicrosoft.com",
        "X500:/o=Org1/ou=Exchange Administrative Group (xxxxx)/cn=Recipients/cn=yyyyyyyy",
        "smtp:email1@company.onmicrosoft.com",
        "SMTP:email1@company.com"
    ]
}

I then send an email to alias1@company.com. I do not see the alias when retrieving toRecipients or internetMessageHeaders, only the parent account email@company.com.

Request:

https://graph.microsoft.com/v1.0/me/messages/{messageId}?$select=toRecipients,internetMessageHeader

Response:

{
    "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('...')/messages(toRecipients,internetMessageHeaders)/$entity",
    "@odata.etag": "W/\"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX\"",
    "id": "{messageId}",
    "internetMessageHeaders": [
        {
            "name": "Received",
            "value": "...."
        },
        {
            "name": "Received",
            "value": "..."
        },
        {
            "name": "Received",
            "value": "..."
        },
        {
            "name": "Authentication-Results",
            "value": "company.com; dkim=none (message not signed) header.d=none;company.com; dmarc=none action=none header.from=company.com;"
        },
        {
         ...
        }
    ],
    "toRecipients": [
        {
            "emailAddress": {
                "name": "FirstName LastName",
                "address": "email1@company.com"
            }
        }
    ]
}

score 2 · Answer 1 · answered Feb 25 '20 at 14:24

2

I found this in another SO article: Can you get PR_TRANSPORT_MESSAGE_HEADERS 0x007D from the .Net Microsoft Graph API?

That will return the headers you need

answered Feb 25 '20 at 14:24

BoKDamgaard

378
1
19

I was aware of that post but it never worked for me, at least from API call. Were you able to get it to work? – Greg Feb 25 '20 at 17:17
Yes, it work's fine. Just pushed it to live server last night. I'm using the .net sdk which helps a bit regarding naming of the query parameters, which are sometimes confusing. – BoKDamgaard Feb 26 '20 at 11:01
I could not get the URL to work as posted, unless the URL construct that was posted was not correct. – Greg Feb 26 '20 at 19:31
I pulled this from the .net sdk: `https://graph.microsoft.com/v1.0/users/xxxxxxx@xxxxxxxxx/mailFolders/Inbox/messages?$select=id,hasAttachments,from,toRecipients,singleValueExtendedProperties,subject&$expand=singleValueExtendedProperties($filter=id eq 'String 0x007D')}` – BoKDamgaard Feb 27 '20 at 07:56

Dai · Accepted Answer · 2020-02-19T03:03:52.523

You can't.

Microsoft Exchange Server, Office 365 and Outlook.com (formerly Hotmail) do not preserve (or at least expose) the SMTP RCPT TO value (i.e. the envelope address) - which is distinct from the To:, Cc:, and Bcc: headers (note that the Bcc header isn't usually sent at all to the recipient anyway).

This is how e-mail users can receive emails that don't look like they're intended for them (as e-mail servers use the RCPT TO value to route the email and ignore the To: header.

Note that anti-spam software will often flag emails when the RCPT TO value doesn't appear in any of the To:, Cc:, or Bcc: headers as in the late-1990s/early-200s mass-mailed spam didn't have personalised To: headers.

Warning: editorial content below:

I did submit a request with Office 365 support (as I'm an Enterprise subscriber, which I hope means something) to request that they add support for storing the RCPT TO envelope address, but it was thrown onto the backlog _{and so will never happen}. It's yet another bloody obvious feature of an e-mail system that Microsoft steadfastly refuses to adopt, just like disposable addresses, messaging tagging, inline quote replies, separating mailboxes from users, and a tree-view for conversation threads - and more besides. Oy vey.

Microsoft Graph: How to get the alias from an email message?

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